1. Field of the Invention
The present invention relates to a control apparatus for an electric vehicle.
2. Description of the Background Art
In a conventional electric vehicle, when the power supply switch is turned on and the accelerator is operated, a large current flows instantaneously creating a thermal effect which effects various parts of the electric vehicle including the electric motor coil. In order to eliminate such a thermal effect, technologies for developing apparatuses have been proposed for controlling starting operations of the electric vehicle, such as halting the current supplied to the motor by turning off a main relay.
However, technologies related to apparatuses for controlling operations of the conventional electric vehicle are not necessarily devised for vehicles such as electric motor driven bicycles. The conventional apparatus for controlling starting operations for electric vehicles has a problem in that it cannot be used for all applications.
In the case of an electric motor bicycle, for example, the accelerator can also be operated even if the driver is not sitting on the seat. In this case, it is desirable to control the operation of the electric motor bicycle.
As for the conventional electric vehicle, for instance, a power supply ON verifying alarm is sounded to attract the driver's attention that the electric vehicle is ready for operation. In order to produce such an alarm sound, the conventional electric vehicle is equipped with a special electroacoustic transducer such as a piezoelectric horn. The piezoelectric horn is used because an electromagnetic horn serving as a klaxon or the like generates too loud of a sound and cannot produce sound having a frequency different from an intrinsic vibration frequency due to the fact that the electromagnetic horn serving as a klaxon is driven by a dc voltage which is turned on and off by an embedded self-intermittent mechanism in order to allow the dc voltage to be applied directly to the electromagnetic horn. As a result, two kinds of electroacoustic transducers are unavoidably needed. Nevertheless, it is desirable to use a common single transducer if possible.